2/28/2005 @ 12:00AM

Sexism at Harvard

The violent reaction to Larry Summers’ comments about women mathematicians didn’t leave much room in the media for a discussion of the facts.

When all else fails, appoint a commission. In a real emergency–like when you’re the president of Harvard and are being hysterically assailed for wondering aloud about the possibility of an innate component to the male advantage in mathematics–appoint two commissions. Testifying to the ghastliness of his situation, and to the fact that he was running out of ways to merely apologize, that is what Lawrence H. Summers did the other day. Both commissions will look for ways to hire more female academics, and one of them will specialize in hiring on the hard sciences front.

Is it really absurd to think there might be innate gender differences in mathematical ability? An avalanche of scientific research, not to mention the wisdom of your grandmother, supports the idea of significant innate differences between the sexes. Some scholars, notably David Geary of the University of Missouri-Columbia, have argued persuasively that this premise is in fact required by the logic of Darwinian natural selection. (Darwin referred to this branch of his argument as sexual selection.) Yet when Summers mentioned the possibility of innate differences–and asked whether they might be related to underrepresentation of female academics in math and science–he got seriously pounded by fellow academics, the public and the press. His apologies ended with a fair amount of groveling.

But Summers has certain numbers on his side. Three telling details: 1) A 2001 survey conducted by the National Science Foundation established that there were 285,500 individuals with Ph.D.s working as mathematicians, computer scientists, physical scientists and engineers, and only 11.5% of them were women. 2) In the index of a math text the names attached to mathematical discoveries–Gauss, Euler, Riemann, Newton, Legendre, Poisson, Fourier, Cauchy and so on–almost invariably belong to men. 3) Since 1938 only 3 of the 335 winners in the prestigious William Lowell Putnam Mathematical Competition have been women. The test, whose graders do not know the names of the contestants, is one of ingenuity, not knowledge, so a possible lack of access to advanced math courses is not very relevant to the outcome.

Did gender stereotyping yield these lopsided results? It could have influenced the Ph.D. count. But it’s hard to dismiss the other two phenomena as due primarily to sexism. Summers’ enemies did not present any evidence that gifted young women are urged not to take the Putnam exam.

The Harvard story got big-league national coverage. But like academe, the media proved overwhelmingly hostile to the idea of innate differences, and it is very hard to find articles registering any interest in the avalanche of research. A partial exception was a Jan. 24 New York Times article, which ran on the front page and performed an amazing feat: It cited a number of neurological and hormonal differences between the sexes, related them to lower female test scores in math, yet ended up supportively quoting experts who say that “baseless sexism” is the real reason for the paucity of females in math and the physical sciences.

What does the research tell us? Among scholars not passionately committed to explanations based on sexism, one finds three powerful and biologically based reasons for the shortage of women in the physical sciences.

The first is a male advantage in visuospatial skills, i.e., the ability to imagine what objects would look like when rotated in space. These skills are especially critical for geometric tasks and multistep problem-solving, where it often helps to “see” the solution in the mind’s eye. There is no doubt that visuospatial ability, which is affected by sex hormones, is biologically based. Doreen Kimura, professor of psychology at Simon Fraser University and author of Sex and Cognition, is among those who see innate factors at work. “I think there’s some biological basis for high-level mathematical reasoning,” she says. “It’s hard to see what else it might be that’s driving those winners in a Putnam competition. It’s such a peculiar skill set.”

Next is a greater male variability in intellectual skills. In math and many other disciplines men are overrepresented at the extremes: more gifted students but also more who are learning-disabled. On the math SAT men are 30% more likely than women to score in the 600 to 649 range. But they are 150% more likely to score over 750. And, as noted, they are 11,067% more numerous among Putnam winners. The variability pattern clearly has a biological basis, and it is not confined to Homo sapiens. In his 1998 book Male, Female: The Evolution of Human Sex Differences, David Geary presents data indicating that many different bird and mammal species also exhibit greater male variability, in traits relating to health and vigor.

A final reason for the shortage of women in math and the physical sciences is a lack of female interest in the core content of these fields–many of which tend to emphasize abstract and mechanical themes. Studies matching equally gifted men and women, all of whom have the ability to make it in the physical sciences, have shown that the men are about eight times as likely as the women to enter these fields. The talented women repeatedly look around for something else, preferably involving disciplines affecting human beings (like, say, biology). A lot of research supports the idea that the male-female difference in interests is hormonal. This is also the view of Patricia Hausman, a behavioral scientist who often consults on employment issues. Addressing a National Academy of Engineering meeting a while back, she noted the widespread assumption that these differences are driven by “socialization,” then swatted the idea: “I find the evidence against this view overwhelming. Sex differences in behavior–with girls more attentive to people and boys to geometric shapes, blinking lights and three-dimensional objects–emerge in the earliest days or months of life, long before socialization begins.”

All very persuasive. Unless, of course, you are committed to a particular theory about baseless sexism.